Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 02 Dec 2012
Posts: 178

In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
12 Dec 2012, 04:55
5
This post received KUDOS
61
This post was BOOKMARKED
Question Stats:
70% (02:09) correct 30% (02:21) wrong based on 1698 sessions
HideShow timer Statistics
In Country C, the unemployment rate among construction workers dropped from 16 percent on September 1, 1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1, 1996, than on September 1, 1992, what was the approximate percent change in the number of unemployed construction workers over this period? (A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase
Official Answer and Stats are available only to registered users. Register/ Login.



Math Expert
Joined: 02 Sep 2009
Posts: 44290

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
12 Dec 2012, 05:03
35
This post received KUDOS
Expert's post
31
This post was BOOKMARKED
Walkabout wrote: In Country C, the unemployment rate among construction workers dropped from 16 percent on September 1, 1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1, 1996, than on September 1, 1992, what was the approximate percent change in the number of unemployed construction workers over this period?
(A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase September 1, 1992The total number of construction workers = 1,000 (assume); 16% are unemployed, thus the number of unemployed workers = 160. September 1, 1996The total number of construction workers = 1,200 (20% greater); 9% are unemployed, thus the number of unemployed workers = 108. Decrease is 52, which is approximately 30% of 160. Answer: B.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Intern
Joined: 15 Sep 2013
Posts: 5

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
24 Sep 2013, 06:37
1
This post received KUDOS
From 92  96 > 20% inc in # construction workers From 92  96 > 7% dec in unemployment > +7% to # of construction workers 20% + 7% = 27% > (B > 30%)



Current Student
Joined: 10 Nov 2013
Posts: 20
Location: United States
Concentration: Healthcare, Strategy
WE: Information Technology (Health Care)

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
29 Nov 2013, 17:19
2
This post was BOOKMARKED
Walkabout wrote: In Country C, the unemployment rate among construction workers dropped from 16 percent on September 1, 1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1, 1996, than on September 1, 1992, what was the approximate percent change in the number of unemployed construction workers over this period?
(A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase Since the problem is percentage related, I just assumed the total number of workers in 1992 was 100. => total unemployed in 92 = 16 There was a 20% increase in the number of workers between 92 and 96 => Total workers in 96 = 100 + 100(20/100) = 120. There was a change of 9% in the unemployment rate from 92 to 96. => Total unemployed in 96 = 120 * 9/100 = 11 (approximately) Now the actual question  change in the unemployed construction workers => (unemployed in 92  unemployed in 96) / unemployed in 92 => (1611)/16 * 100 = 30 approximately. => 30% decrease.



Intern
Joined: 30 Apr 2014
Posts: 3

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
30 Apr 2014, 19:52
1
This post received KUDOS
1
This post was BOOKMARKED
Walkabout wrote: In Country C, the unemployment rate among construction workers dropped from 16 percent on September 1, 1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1, 1996, than on September 1, 1992, what was the approximate percent change in the number of unemployed construction workers over this period?
(A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase This problem is a prime candidate for picking numbers. Since the question is dealing with percents I decided to go use 100. Once you pick easy to work with numbers just pick apart the questions slowly Unemployment rate 1992 was 16% > I'm starting with 100 workers therefore 16 are unemployed In 1996 the number of workers increased 20% > there are now 120 workers. > 9% unemployed would equal to 10.8% (the question uses the word approximately which told me I'm definitely rounding some numbers) so 11% Percent change formula [Difference][/Original] X 100 = [5][/16] X 100 = ~30%



Manager
Joined: 27 Oct 2013
Posts: 249
Location: India
Concentration: General Management, Technology
GMAT Date: 03022015
GPA: 3.88

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
30 Apr 2014, 22:05
Assume there are 1000 construction workers in the year 1992. Then tabulate as per the question 1996 1992 Contruction Workers 1200 1000 Unemployed Workers 108 160 Simply find out...((final  initial)/initial)*100 Option B is right



Intern
Joined: 22 Feb 2014
Posts: 28

OG question...Can anyone help me with the alternate solution [#permalink]
Show Tags
12 Jul 2014, 22:49
In CountryC, the unemployment rate among construction workers dropped from 16 percent on September 1,1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1,1996, than on September 1,1992, what was the approximate percent change in the number of unemployed construction workers over this period? (A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase In OG explanation is given but its too much time consuming and confusing for me. Anyone has tried any other way ??? Or anyone has tried to solve this question with pick number strategy...I tried but I am not getting correct answer. Please explain Thanks in advance.



Manager
Joined: 21 Sep 2012
Posts: 218
Location: United States
Concentration: Finance, Economics
GPA: 4
WE: General Management (Consumer Products)

Re: OG question...Can anyone help me with the alternate solution [#permalink]
Show Tags
13 Jul 2014, 00:06
GGMAT760 wrote: In CountryC, the unemployment rate among construction workers dropped from 16 percent on September 1,1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1,1996, than on September 1,1992, what was the approximate percent change in the number of unemployed construction workers over this period? (A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase In OG explanation is given but its too much time consuming and confusing for me. Anyone has tried any other way ??? Or anyone has tried to solve this question with pick number strategy...I tried but I am not getting correct answer. Please explain Thanks in advance. 1992 1996 No of construction workers 100 120 Unemployment Rate 16% 9% Unemployed workers 16 11 % change in unemployed workers=(1611)=5/16=~33% decrease Closest ans=30% decrease Ans=B



Senior Manager
Joined: 08 Apr 2012
Posts: 437

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
27 Jul 2014, 01:52
Anyone did this without picking numbers?



Manager
Joined: 07 Apr 2014
Posts: 130

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
11 Sep 2014, 11:57
Walkabout wrote: In Country C, the unemployment rate among construction workers dropped from 16 percent on September 1, 1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1, 1996, than on September 1, 1992, what was the approximate percent change in the number of unemployed construction workers over this period?
(A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase say in 1992  25 ppl & 16% unemployment rate then 4 ppl . say in 1996  20% increase then 30 ppl & 9%unemployment rate then 2.7 42.7/4 = 32.5 % then i have chosen B.. pretty time consuming for choosing numbers.



Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7988
Location: Pune, India

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
11 Sep 2014, 23:12
1
This post received KUDOS
Expert's post
3
This post was BOOKMARKED
ronr34 wrote: Anyone did this without picking numbers? Yes, you can do it using the successive percentage change concept too. Number of unemployed construction workers = Number of Construction Workers * Unemployment rate If there is a change in the number of construction workers and unemployment rate, we can find the change in the number of unemployed construction workers. Number of construction workers is 20% greater i.e. 6/5 of previous value Unemployment rate reduces from 16 to 9 i.e. becomes 9/16 of previous value Multiplier for number of unemployed construction workers = 6/5 * 9/16 = 27/40 This is a reduction of 13/40 which is a little more than 30%. For more on this concept, check: http://www.veritasprep.com/blog/2011/02 ... echanges/http://www.veritasprep.com/blog/2011/02 ... ntprofit/
_________________
Karishma Veritas Prep  GMAT Instructor My Blog
Get started with Veritas Prep GMAT On Demand for $199
Veritas Prep Reviews



Board of Directors
Joined: 17 Jul 2014
Posts: 2752
Location: United States (IL)
Concentration: Finance, Economics
GPA: 3.92
WE: General Management (Transportation)

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
14 Dec 2015, 19:51
solved it the way bunuel explained. 92  1000 workers, 160 unemployed. 96  1200 workers, 108 unemployed. we can see the number decreased. we can eliminate the answer choices that say "increase". moreover, if you think logically, 52 is not 50% of 160, thus we can eliminate it. Moreover, 16=10% and 8 = 5%. decrease of 15% should be 24 workers, which again not works. thus, the only option that is possible  30%



Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 2293
Location: United States (CA)

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
10 Jun 2016, 11:49
Walkabout wrote: In Country C, the unemployment rate among construction workers dropped from 16 percent on September 1, 1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1, 1996, than on September 1, 1992, what was the approximate percent change in the number of unemployed construction workers over this period?
(A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase Solution: We are given two pieces of information that can be translated into equations. However, before we make those equations let’s set up some variables as well to display some of the information provided. 16% = unemployment rate on September 1, 1992 9% = unemployment rate on September 1, 1996 c = number of construction workers on September 1, 1992 d = number of construction workers on September 1, 1996 Thus, we know: 0.16 × c = number of unemployed construction workers on September 1, 1992 0.09 × d = number of unemployed construction workers on September 1, 1996 We are asked to determine the approximate percent change in the number of unemployed construction workers over this period. The formula for percent change is: [(New Value – Old Value)/(Old Value)] x 100 Using our variables above, the percent change formula will be: (0.09d – 0.16c)/(0.16c) × 100 In order to solve this formula we need to create an equation. We are given that the number of construction workers was 20% greater on September 1, 1996 than on September 1, 1992. Thus, we can say: d = c + 0.2c = 1.2c We can now substitute 1.2c for d in our percent change equation: [(0.09 × 1.2c – 0.16c)/(0.16c)] × 100 [(0.108c – 0.16c)/(0.16c)] × 100 [(108c – 160c)/(160c)] × 100 [(52c)/(160c)] × 100 (13/40) × 100 Since we are asked to approximate we can change 13/40 to 13/39, which reduces to 1/3. We now have: 1/3 × 100 = 33.3% The closest answer to this is B, a 30% decrease. Because the answer choices are in percentage form, there is another way to solve this question: we can use convenient numbers. Let’s say the number of construction workers in 1992 is 100. We know, therefore, that the number of workers in 1996 is 1.2 × 100 = 120 workers. We know that the unemployment rate among construction workers dropped from 16% on September 1, 1992 to 9% on September 1, 1996. Thus we can say that the number of unemployed construction workers in 1992 is: 0.16 × 100 = 16 And the number of unemployed construction workers in 1996 is: 120 × 0.09 = 10.8 which is about 11. We can now get the percent change: [(New Value – Old Value)/(Old Value)] × 100 Using our values above the percent change formula will be: [(11 – 16)/16] × 100 (–5/16) × 100 5/16 is about 5/15, which reduces to 1/3. Again, 1/3 × 100 = 33.3%, which is closest to answer B.
_________________
Scott WoodburyStewart
Founder and CEO
GMAT Quant SelfStudy Course
500+ lessons 3000+ practice problems 800+ HD solutions



Director
Joined: 07 Dec 2014
Posts: 922

In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
10 Jun 2016, 12:23
1
This post received KUDOS
.09*1.2/.16=.675 1.675=.325~30% decrease answer b



Manager
Joined: 20 Mar 2015
Posts: 62

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
29 Jun 2016, 05:18
monkeya41 wrote: From 92  96 > 20% inc in # construction workers From 92  96 > 7% dec in unemployment > +7% to # of construction workers 20% + 7% = 27% > (B > 30%) Is the above reasoning correct?



Intern
Joined: 21 Mar 2013
Posts: 12

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
12 Aug 2016, 10:15
bimalr9 wrote: monkeya41 wrote: From 92  96 > 20% inc in # construction workers From 92  96 > 7% dec in unemployment > +7% to # of construction workers 20% + 7% = 27% > (B > 30%) Is the above reasoning correct?This approach latches on the word 'approximate' in the question. First of all, there were more people working in 1996 (20% more than 1992). The % of unemployment in 1996 is lower than 1992 (only 9% compared 16% of 1992). So you have more people working and out of that smaller % unemployed. Meaning, definitely overall fewer people were unemployed in 1996 i.e. DECREASE. Then, roughly speaking, 20% increase in workers + 7% change in unemployment is 27%. You have two choices closest to 27%. 30% increase or 30% decrease. We already know it is an overall decrease for sure. So it must be APPROXIMATELY 30% overall decrease. A very neat and quick solution but more error prone if you can't quickly wrap your head around a bunch of numbers being thrown at you. I'd better stick with a number picking solution unless I am on a time crunch mode and I must guestimate a couple of questions.



Manager
Joined: 03 Jan 2017
Posts: 193

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
25 Mar 2017, 09:45
Description 1992 1996 % of unemployed 16% 9% number 1 1,2
0,09*1,20,16=0,052 0,052/0,16=0,3..
Answer is B 30% Descriase



Study Buddy Forum Moderator
Joined: 04 Sep 2016
Posts: 760
Location: India
WE: Engineering (Other)

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
26 Dec 2017, 22:38
Bunuel, niks18Quote: In Country C, the unemployment rate among construction workers dropped from 16 percent on September 1, 1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1, 1996, than on September 1, 1992, what was the approximate percent change in the number of unemployed construction workers over this period?
(A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase Quote: The total number of construction workers = 1,000 (assume); I complicated calculations by taking smart no as 100 instead of 1000 since we normally do so in %tages. What strategy did you use to pick 1000 and not 100?
_________________
It's the journey that brings us happiness not the destination.



PS Forum Moderator
Joined: 25 Feb 2013
Posts: 1001
Location: India
GPA: 3.82

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
27 Dec 2017, 11:19
adkikani wrote: Bunuel, niks18Quote: In Country C, the unemployment rate among construction workers dropped from 16 percent on September 1, 1992, to 9 percent on September 1, 1996. If the number of construction workers was 20 percent greater on September 1, 1996, than on September 1, 1992, what was the approximate percent change in the number of unemployed construction workers over this period?
(A) 50% decrease (B) 30% decrease (C) 15% decrease (D) 30% increase (E) 55% increase Quote: The total number of construction workers = 1,000 (assume); I complicated calculations by taking smart no as 100 instead of 1000 since we normally do so in %tages. What strategy did you use to pick 1000 and not 100? Hi adkikanifor % problems, assumption of total to be 100 is the natural inclination for most of us and calculation should not be too complicated. So if you assume 100 then instead of 160 & 108 you will get 16 and 10.8 respectively. these numbers are still small and calculations should not be tough. However if you are able to think (under 2 minutes in exam pressure) that the % involved are not multiples of 10 so working with them might lead to decimal numbers, then obviously working with 1000 (or higher multiples of 10) will be beneficial as it will result in whole numbers. it depends on how quickly you are able to recognize the trend.



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 11255
Location: United States (CA)
GRE 1: 340 Q170 V170

Re: In Country C, the unemployment rate among construction worke [#permalink]
Show Tags
11 Feb 2018, 14:06
Hi All, This question can be solved by TESTing VALUES. You'll need to reorganize the information that you're given though (since it's offered 'out of order'). We're told that the NUMBER of construction workers was 20% greater in 1996 than in 1992. Number of workers in '92 = 100 Number of workers in '96 = 120 We're told that the UNEMPLOYMENT RATE was 16% in 1992 and 9% in 1996. This allows us to figure out the NUMBER of unemployed workers... Unemployed in '92 = 100(16%) = 16 Unemployed in '96 = 120(9%) = 10.8 The question asks for the APPROXIMATE Percent Change in the number of unemployed workers... Percent Change = (New  Old)/Old = Difference/Original With these numbers, we end up with... (10.8  16)/16 = 5.2/16 = about 1/3 = about a 30% decrease Final Answer: GMAT assassins aren't born, they're made, Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels Contact Rich at: Rich.C@empowergmat.com
Rich Cohen
CoFounder & GMAT Assassin
Special Offer: Save $75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee www.empowergmat.com/
***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************




Re: In Country C, the unemployment rate among construction worke
[#permalink]
11 Feb 2018, 14:06






